7751 Datasheet, PDF (101/540 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER

TIMER A
5.4 Event counter mode
Table 5.4.2 Specifications of event counter mode (when using two-phase pulse signal processing
function with timers A2, A3, and A4)
Item
Specifications
Count source
External signal (two-phase pulse) input to the TAjIN or TAjOUT pin (j =
Count operation
2 to 4)
q Up-count or down-count can be switched by external signal (two-
phase pulse).
q When the counter overflows or underflows, reload register’s contents
are reloaded and counting is continued.
Count start condition
When count start bit is set to “1.”
Count stop condition
When count start bit is cleared to “0.”
Interrupt request occurrence timing When the counter overflows or underflows.
TAjIN, TAjOUT (j = 2 to 4) pin function
Two-phase pulse input
Read from timer Aj register
Write to timer Aj register
Counter value can be read out.
q While counting is stopped
When a value is written to timer A2, A3, or A4 register, it is written
to both reload register and counter.
q While counting is in progress
When a value is written to timer A2, A3, or A4 register, it is written
to only reload register. (Transferred to counter at next reload time.)
5–20
7751 Group User’s Manual